A conventional test handler comprises a turret and pick heads coupled to the turret for holding semiconductor packages. During operation, the turret rotates above various handling devices, such as a testing module for testing the performance of the semiconductor packages. Specifically, a pick head holding a semiconductor package moves to the testing module in order to test the semiconductor package. In particular, the testing module has to be aligned with respect to the semiconductor packages as held by the respective pick heads, in order to achieve good machine stability, a high function test yield, and a low rate of package damage.
At present, the alignment or positional adjustment between the testing module and the semiconductor packages is achieved by using human judgment. Since human judgment is subjective and requires the operation of the test handler to be visualized, it becomes difficult or even impossible if the size of the semiconductor packages is very small. Additionally, this method requires considerable human skill and labour, due to an absence of data to serve as a basis for accuracy.
Thus, it is an object of this invention to seek to ameliorate the aforesaid disadvantages of the conventional method for aligning one or more handling devices that handle semiconductor packages, and to provide the general public with a useful choice.